Sensitive photographic film.



J. E. BRANDENBERGER. SENSITIVE PHOTOGRAPHIC FILM. ,APPLICATION FILED FEB. 2 1915.

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Patented Apr. 10, 1917.

racemes EDWIN BRANDENBERGEB, or rams, FRANCE, assrenoa T0 LA SOGIETE DITE LA CELLOPHANE, or rams, FRANCE.

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Specification of Letters Patent.

Application filed February 24, 1915. Serial No. 10,274.

To all whom it may concern:

Be it known that I, JACQUES EDWIN BRAND ENBERGER, a cltizen of Switzerland, and resia,

dent of 16 Rue du Louvre, Paris, France, have invented a new and useful Sensitive Photographic Film, which is fully-set forth in the following specification.

It is well known that difliculties of all kinds are met with in covering with emul- S1011 photographic or cinematographic films.

On the other hand, it is known that the said films have to be manipulated with the greatest possible care in order to avoidany deterioration of the sensitive layer covering the same.

The film forming the subject of the present invention is arranged in such a manner that its sensitive layer is protected during the emulsioning operations, from atmospheric dust, and said layer remaining subsequently protected from any direct contact, either during the course of manufacture of the film or during its use.

To that end, I employ two sheets, at least one of which is of cellulosic nature, and is transparent and permeable to liquids, while the other may be partially or completelydeprived of one ofthe said properties,or even both; and between these two sheets I introduce the sensitive mass constitued either by salts sensitive to light,g'enerally used in photography, and mixed with a transparent adhesive (for instance collodion, gelatin soith lu-tions, rubber solutions, or vegetable extract -solutions) or by a transparent and permeable sheet impregnated itself with sensitive solutions; in the latter case, the conmotion of the three sheets is still efi'ected by means of a transparent adhesive of the same nature as above. I

The composlte film therefore compr ses:

either (1) two films of pure cellulose (obtained by starting from viscose or cuproammoniacal solutions of cellulose) between which is placed either the sensitive emulsion,

views of the improved film, Figure 1 show- Patented Apr. in, 1917.

ing the form of the composite film when the sensitive emulsion is used, and Fig. 2 showing the form which said film takes when the intermediate cellulosic film is utilized.

In both figures, 3 and 4 indicate the two outer films, one of which, as stated above, is constructed of pure cellulose. The other of these two films may likewise be contheyditfer radially from successive layers or coatings which are applied one upon another, or upon opposite faces of a blade or bod In Fig. 1, 5 indicates the sensitive emulsion, which is supplied in liquid form between the inner faces of the two films 3 and 4, Any desired apparatus may be utilized to effect the adhesion of the two films, but it is preferable to carry out this step by passing the films from opposite directions to and between a pair of suitable pressure rolls, and to discharge the emulsion upon the inner surfaces of said films at'the bite of the rolls, so that the latter will feed the films between them and, at the same time, will join them together face to face. On emerging from the rolls, the composite film may be dried, and thereafter wound up in any desired manner.

In Fig. 2, 6 indicates the intermediate film, which is preferablyin'the form of a cellulose film impregnated witha sensitizing solution. The union of the three films may be effected in substantially the same way as in the first form, excepting that the opposite surfaces of the intermediate film and the inner surfaces of the-two outer films 'are coated with the adhesive which is delivered, as before, pressure rolls.

Claims:

1. A composite photographic film, com prising two separately constructed, outer films, and anintermediate stratum or layer containing sensitive material disposed between the inner surfaces of said films, said to or at the bite of the outer films and said intermediate stratum being united face to face throughout their entire extent; at least one of said outer films being constructed of cellulose, andvbeing transparent and permeable to the'liquids employed in photography.'

2. A composite photographic film, comprising three separately-constructed,' co6rdi-' nate films united face to face throughout their entire extent; at least one of the two outer -films being constructed of cellulose,

and being transparent and permeable to the. liquids employed in photography, and intermediate the film being constituted by a continuous transparent sensitized sheet.

liquids employed in photography, and the intermediate film being constituted by a continuous transparent strip of cellulosic material impregnated with a sensitizing liquid and a transparent adhesive.

In testimony whereof I have signed this specification.

JACQUES EDWIN BRANDENBERGER. 

